The integration of telecommunication equipment with data processing equipment provides for powerful tools that coordinate the advanced features of digital telephony with the computer processing power of digital computer networks. For example, computer integrated telephony (CIT) systems exist that integrate PBX systems with LAN systems. These PBX CIT systems provide advanced call control and processing. For example, these CIT systems can run applications that detect incoming telephone calls, employ a caller ID function to determine the identified source of the incoming call, pass the source identification information to a computer database application program that employs the source identification as an entry point to the database. From the database, the CIT system can collect relevant customer records such as the invoice statements. The CIT system at that time can transfer both the incoming call and the associated data records to a customer service agent that is most suited for handling this incoming call. For example, if the invoice records show that the account associated with the call is overdue, the CIT system transfers both the incoming call and the relevant invoice data record to an available customer service agent in the billing department of the company.
The CIT systems that exist today include a PBX system that connects to a network server. The PBX system performs the telecommunication functions which include establishing circuit connections between calls from the public telephone system and the individual extension lines within an office. The server performs the data processing applications which can include maintaining databases and running client/server applications. The interface between the PBX and the server establishes a physical and logical connection between the server and the PBX that allows for the operation of CIT systems.
The physical connection between the PBX and the server is typically a conventional computer interface that includes an interface card located in the PBX, an interface card located in the server and a cable connection that extends between these two interface cards. The interface cards typically implement a conventional data communications protocol such as X.25 or ISDN. Through this channel, the PBX and the server can exchange data for coordinating the activities of these two systems during operation of CIT system applications.
The logical connection between the PBX and the server determines how messages are exchanged across the physical interface. Typically, a client/server application running on the computer network generates either requests for actions or requests for instructions for the PBX system. The client passes these requests on to the server. The server has a translator program that translates the message requests from the application program into commands that can be used to operate the PBX. These commands are sent to a software driver that puts the commands into a format suitable for transmission over the data channel, such as the ISDN line or X.25 line. The PBX system receives through its interface card the commands and performs the functions as dictated. The PBX then transmits status messages back to the server system which translates the PBX messages into a format that the application program can understand and the server sends the translated messages to the application program. The application program determines from the translated messages what data records the application program needs to access and proceeds to route the data records to the appropriate client computer and to send further instructions to the PBX system to route any associated incoming calls to the telephone associated with that client's computer.
Although the above systems work to integrate data processing equipment with telecommunications equipment, the integration through the physical and logical connections is often perplexing and difficult to create and maintain. Firstly, most PBX architectures are proprietary, therefore the physical connection between the server and the PBX differs depending on the vendor. For example, an EtherNet port, such as the one found on the NEAX 2000 from Nec America, will be different from the ISDN BRI link employed by AT&T's Definity system. Computer network managers that have to integrate the PBX system into the local area network often find the link between the server and PBX to be both cumbersome and unreliable.
Moreover, these present systems are dependent upon the proper operation of the network LAN server. In the event that the LAN server crashes, the CIT system application that operates the PBX system is brought down. Similarly, any time the computer network manager wishes to reinitialize the network server, those CIT applications that operate the telecommunication systems will also be brought down. Accordingly, the present systems are subject to failure and are difficult to maintain. A further difficulty exists, in that the development of CIT applications is made difficult by the proprietary PBX driver that translates messages from client/server applications into commands suitable for implementation by the PBX system. In particular, as each PBX driver is typically a proprietary software system, the development of standard applications is difficult, if not impossible.
Accordingly, it is an object of the present invention to provide CIT systems that provide an improved interface between telecommunication equipment and data processing systems.
It is a particular object of the present invention to provide a PBX system that more easily integrates with the server of a local area network.
It is a further object of the present invention to provide a LAN--integrated PBX system that has improved fault tolerance.
It is an additional object of the present invention to provide a CIT system that has greater performance and improved reliability.
These and other objects of the present invention shall be made more clear by the following description that references figures having reference numbers wherein like reference numbers refer to the same elements.